Abstract

QUIROGA-MADRIGAL, Ricardo et al. Diseases caused by fungi and nematodes in tomato (Lycopersicon esculentum Mill.) in Villaflores County, Chiapas, Mexico. Rev. mex. fitopatol [online]. 2007, vol.25, n.2, pp.114-119. ISSN 2007-8080.

Tomato (Lycopersicon esculentum) is the most important vegetable crop in Villaflores county, state of Chiapas, Mexico, due to its profitability. However, there are production constraints like diseases caused primarily by fungi and nematodes which may render losses up to 100%. In addition, the lack of knowledge of the local causal agents leads to implementation of inappropriate control measures, which includes excessive use of agrochemicals without legal regulations that guarantee food safety. The objective of this study was to identify the causal agents of the most important fungal diseases and those caused by nematodes, and to determine their incidence and severity on tomato crop in Villaflores, Chiapas. Twenty-two plots were evaluated from March to May, 2001, and nine from July to September, 2005. The diagnosis indicated the presence of the following diseases and pathogens: damping off caused by Pythium aphanidermatum and Rhizoctonia solani, early blight by Alternaría solani, late blight by Phytophthora infestans, southern blight by Sclerotium rolfsii, fruit rots by Alternaría sp., Pythium sp., and Geotrichum sp., and root-knot by the nematode Meloidogyne sp. Disease incidence and severity varied according to site, season, genotype, and crop management.

Keywords : Diagnosis; etiology; fungal diseases; root-gall nematodes; Pythium aphanidermatum; Rhizoctonia solani; Alternaría solani; Phytophthora infestans; Sclerotium rolfsii; Meloidogyne sp..